]> granicus.if.org Git - llvm/commit
[AArch64] Set pref. func. align to 8 bytes on Neoverse E1 & Cortex-A65
authorPablo Barrio <pablo.barrio@arm.com>
Fri, 9 Aug 2019 11:05:15 +0000 (11:05 +0000)
committerPablo Barrio <pablo.barrio@arm.com>
Fri, 9 Aug 2019 11:05:15 +0000 (11:05 +0000)
commitb2d6af4c55cb1c5ec852ae83e3f3c4f767f28233
tree8c054accf987cf2ed413b17e4ce992082e9963e5
parent3a826a6553b25251edb182005b3a476816b35228
[AArch64] Set pref. func. align to 8 bytes on Neoverse E1 & Cortex-A65

Summary:
The Arm Neoverse E1 and Cortex-A65 Software Optimization Guide [1][2],
Section "4.7 Branch instruction alignment" state:

"It is preferable for branch targets, including subroutine entry points,
to be placed on aligned 64-bit boundaries to maximize instruction fetch
efficiency."

This patch sets the preferred function alignment on Neoverse E1 and
Cortex-A65 to 2^3=8B. This was already the case in some Cortex-A CPUs
such as Cortex-A53.

[1] https://developer.arm.com/docs/swog466751/latest/arm-neoversetm-e1-core-software-optimization-guide
[2] https://developer.arm.com/docs/swog010045/latest/arm-cortex-a65-core-software-optimization-guide

Reviewers: dmgreen, fhahn, samparker

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65937

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368431 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Target/AArch64/AArch64Subtarget.cpp
test/CodeGen/AArch64/preferred-function-alignment.ll